The invention relates to a front wheel suspension on a two-track vehicle. The front wheel suspension includes a wheel carrier or pivot bearing guided by at least one suspension link in each case connected by way of an articulated connection with the wheel carrier and an axle support or the vehicle body. The suspension is arranged such that during a deformation of the front wheel suspension as a result of an impact of the vehicle on an obstacle, in which there is a further impact-caused deformation of the vehicle front section, the wheel is displaced away from the vehicle interior toward the longitudinal side of the vehicle, wherein the deformation of the front wheel suspension is triggered when the obstacle or, another object caused by the obstacle penetrates into the vehicle front section into the space bridged by the suspension link and extending in the longitudinal direction of the vehicle toward the front between two articulated connections of the suspension link. With respect to the state of the art, reference is made particularly to German Patent Document DE 195 42 496 C1, in addition to German Patent Documents DE 10 2008 015 182 A1 or DE 37 10 892 C2.
It is basically endeavored to make the design of a vehicle, for example, a passenger car, as safe as possible, particularly also for the event of an accident, i.e. when the vehicle impacts on an obstacle. In order to minimize the risk of injury to vehicle occupants in the event of such an impact, the vehicle parts (=the vehicle front section) situated in front of the vehicle interior viewed in the driving direction, if possible, should not penetrate into the vehicle interior as a result of this impact. With respect to the front wheels of the vehicle, the above-mentioned German Patent Document DE 195 42 496 C1 suggests such a design of the wheel-guiding suspension links that, in the event of a so-called offset impact, i.e. when the vehicle impacts onto an obstacle with its corner region, the wheel is pivoted laterally to the outside. For achieving this, a rear control arm strut can be longitudinally deformed, i.e. shortened in an energy-absorbing manner.
A special case of the offset impact is an impact with little overlap, i.e. with an obstacle that is narrow in relation to the width of the vehicle, which impact may be particularly critical when the obstacle penetrates into the vehicle front section without thereby striking the actual crash structure of the vehicle which, in the case of conventional passenger cars is formed by an axle support or an engine mount. When, as a result of the impact, such an object penetrates into the space between a front axle support and the or a front wheel of the vehicle (passenger car), this could possibly affect the suspension of this wheel such that the wheel has the tendency to be shifted toward the longitudinal axis of the vehicle, which may lead to unfavorable deformations with respect to an intrusion into the vehicle interior. In contrast, it is desirable that, as a result of an impact, the wheel ideally is displaced in a straight line in the direction of the door sill of the vehicle body.
It is an object of the present invention to indicate a remedial measure for the described problems.
For a front-wheel suspension of a two-track vehicle having a wheel carrier or pivot bearing guided by at least one suspension link, this object is achieved in that, on or in the region of the front wheel suspension, an add-on part, i.e. a suspension link separating device is provided which projects into the above-mentioned space bridged by the suspension link and extending toward the front, the add-on part being displaced by the impacting obstacle or by the above-mentioned other object such that, as a result, at least one of the articulated connections is opened or destroyed and the suspension link is thereby exposed with respect to the axle support or the wheel carrier. Advantageous embodiments and further developments are the content of the subclaims.
First, the concept of the space will be briefly discussed that extends in the longitudinal direction of the vehicle toward the front between the wheel carrier (=pivot bearing) and the axle support (=front axle support) or the vehicle body or that region of the vehicle body to which the above-mentioned suspension link is fastened by way of the articulated connection, and which is bridged by the suspension link. This space can be described approximately as a rectangle in a perpendicular projection onto the road on which the vehicle is moving, with a certain extent in the transverse direction of the vehicle and an extent in the longitudinal direction of the vehicle which is larger than the extent in the transverse direction. Viewed in the transverse direction of the vehicle, this space is quasi bridged by the above-mentioned suspension link.
According to the invention, an add-on part projects into the above-mentioned space in the region or starting from the region of one of the two articulated connections of the suspension link. The add-on part, in the case of a corresponding impact on an obstacle with little overlap whose negative consequences are to be reduced or minimized by the present invention, ensures that the wheel is partially released from its wheel suspension in that the above-mentioned articulated connection is separated. For this purpose, the obstacle or another object has to impact on the add-on part; whereupon the latter causes the desired separation of the articulated connection, for example, by way of a lever arm formed by the add-on part. As a result, in the course of the further imp act-caused deformation of the vehicle front section, the wheel can be displaced away from the vehicle interior laterally toward the outside, i.e. toward the respective longitudinal side of the vehicle adjoining the wheel. This “partial freeing” of the wheel suspension is implemented by detaching the or a suitable wheel-guiding suspension link, in which case the separating of its articulated connection can take place by opening or destroying the articulated connection. In this case, the articulated connection can basically be opened or destroyed between this suspension link and the wheel carrier or pivot bearing at which the (steerable) vehicle front wheel is disposed, or the articulated connection can be opened or destroyed or, in other words, be interrupted or broken open, thus generally “separated”, between the above-mentioned suspension link and the front axle support or the vehicle body to which the suspension link is hinged by way of an articulated connection.
In this context, it is explicitly pointed out that by no means that obstacle on which the vehicle first impacts, for example, in the form of a pole, has to be the object that penetrates into the above-mentioned space bridged by the suspension link and impacts there on the add-on part according to the invention. On the contrary, the last-mentioned object impacting on the add-on part according to the invention may have been directly or even indirectly caused by the above-mentioned object to impact on the add-on part.
Viewed in the driving direction of the vehicle, the add-on part according to the invention will normally be situated in front of the suspension link to be separated from its articulated connection, which suspension link acts as a hinged tie bar when the articulated connection is operable. Normally, an axle support is provided so that the add-on part projects into the space between the axle support and the wheel. In view of the installation space conditions, it is then recommended to separate the articulated connection between the above-mentioned wheel-guiding suspension link and the axle support by the add-on part according to the invention when an obstacle with little overlap penetrates into the space between the axle support and the wheel and thereby impacts on this add-on part. By this separating or breaking-open of the articulated connection, the above-mentioned suspension link will be exposed with respect to the axle support and, in the course of the further impact-caused deformation, the wheel can shift, as desired, toward the facing longitudinal side of the vehicle.
The add-on part according to the invention may be fastened to different locations. It is only important that, in the event of an impact of the vehicle on an obstacle, whereupon this obstacle or another object penetrates into the above-mentioned space, this add-on part is displaced such that the articulated connection of the suspension link adjacent to the add-on part is separated, i.e. opened or destroyed. In a preferred embodiment, the add-on part can be fastened by way of the, or a fastening screw of, the articulated connection to the articulated connection, in which case the articulation of the articulated connection may be constructed as such, for example, as an elastomeric bearing or rubber bearing, whose interior is penetrated in a known manner by the above-mentioned fastening screw. In this embodiment, the fastening screw can be torn off by way of the lever arm formed by the add-on part with an impact-caused displacement of the add-on part, and the articulated connection can thereby be separated. As an alternative or in addition, the add-on part can be shaped such that, with the above-mentioned displacement, it destroys components of this articulated connection essential for the supporting function of the articulated connection, which explicitly includes not only the articulation as such but also that section of the wheel carrier or axle support or vehicle body at which the articulation of the articulated connection is preferably separably fastened. For example, the add-on part may have a co-called bead or a punch ring or generally a suitably shaped cutting edge, which, in the case of an impact-caused displacement of the add-on part, acts in a destructive manner upon the articulated connection, particularly on a receiving device at the axle support for a an elastomeric bearing forming the articulation, or the like.
According to an alternative embodiment, the add-on part of the invention may be formed by an extension of the above-mentioned fastening screw of the articulated connection. This fastening screw can, for example, be constructed to be so stiff that the impact impulse of the obstacle (or of the above-mentioned other object) is introduced in a virtually unbiased manner as a transverse force into the articulated connection, whereupon the articulated connection is broken open and, as a result, the suspension link is released or exposed as desired.
According to a further embodiment, the add-on part may, however, also be fastened or linked laterally of the articulated connection, for example, to the axle support and have a wedge surface, on which the obstacle or the above-mentioned other object impacts as a result of the collision, i.e. during its progression. When this add-on part is arranged in a suitable manner, this object or the obstacle can then, during the progression of the impact, which lasts until the vehicle has stopped, slide along the wedge surface or the like in such a manner that, again by way of a lever effect, this add-on part will be displaced such that it has a destructive effect on the above-mentioned articulated connection.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.